am7b14022_si_001.pdf (1.68 MB)
Transparent and Flexible Surface-Enhanced Raman Scattering (SERS) Sensors Based on Gold Nanostar Arrays Embedded in Silicon Rubber Film
journal contribution
posted on 2017-11-27, 00:00 authored by Seungyoung Park, Jiwon Lee, Hyunhyub KoIntegration
of surface-enhanced Raman scattering (SERS) sensors onto transparent
and flexible substrates enables lightweight and deformable SERS sensors
which can be wrapped or swabbed on various nonplanar surfaces for
the efficient collection and detection of analytes on various surfaces.
However, the development of transparent and flexible SERS substrates
with high sensitivity is still challenging. Here, we demonstrate a
transparent and flexible SERS substrate with high sensitivity based
on a polydimethylsiloxane (PDMS) film embedded with gold nanostar
(GNS) assemblies. The flexible SERS substrates enable conformal coverage
on arbitrary surfaces, and the optical transparency allows light interaction
with the underlying contact surface, thereby providing highly sensitive
detection of analytes adsorbed on arbitrary metallic and dielectric
surfaces which otherwise do not provide any noticeable Raman signals
of analytes. In particular, when the flexible SERS substrates are
covered onto metallic surfaces, the SERS enhancement is greatly improved
because of the additional plasmon couplings between GNS and metal
film. We achieve the detection capability of a trace amount of benzenethiol
(10–8 M) and enormous SERS enhancement factor (∼1.9
× 108) for flexible SERS substrates on Ag film. In
addition, because of the embedded structure of GNS monolayers within
the PDMS film, SERS sensors maintain the high sensitivity even after
mechanical deformations of stretching, bending, and torsion for 100
cycles. The transparent and flexible SERS substrates introduced in
this study are applicable to various SERS sensing applications on
nonplanar surfaces, which are not achievable for hard SERS substrates.